Calculation of current capacity

How to calculate

current capacity is calculated in amps, which means equality 1A = 1 C / s.Calculate amperage possible for school physical formula: I = Q / t, where I - is the strength of the current, Q - is the amount of charge, and t - the time for which the charge has overcome the surface.If we take, for example, cable, this surface cross-section of the cable.Based on this formula, we remember from school, Ohm's law: current strength for a particular plot network grows in parallel to the voltage expended plot in inverted proportion confrontation wires particular territory.According to Ohm's law I = U / R, where U - is voltage, R - is the conductor resistance.

In general, to determine the current use a special instrument - ammeter.

ammeter connected to the separation of the chain at the point at which the measured currents gathered force.

There are main methods for determining current: magneto, indirect and solenoid.Often in these cases, its power alternating current is divided into:

• instant;
• effective;
• peak.

power of three-phase network

three-phase network - is a variant of the system into several phases, which consists of the sum of several loads and the battery powering, which have the same replication and shifted in phase by a certain angle to each other.Fazosistema - a pair of batteries.Fazosistemy can be seen as a chain, not merging with each other.To measure the power system of three phases often take just the total number of working capacity of all its phases.This count by the formula: P = Pa + Pb + Pc, where the letters Pa, Pb, Pc of each phase voltage multiplied with the angle shift between the loads and currents in the circuit.Accordingly, quick power is the sum of capacities of all phases throughout the chain:
Q = Qa + Qb + Qc.

follows from the above that the three-phase circuit with symmetrical voltage and load, sufficient to determine the load of one phase and its value triple.

Three-phase systems have a predominance of a list of other systems.Such as:

• economical production and transmission of energy;
• easy earning a magnetic field in a circle;
• obtain two loads suitable for operation (phase -Voltage phase and line - voltage in a conductor), both in the offices and home devices and systems.

Any of the networks used can be balanced (harmonious) and asymmetric (disharmonious).

What is the balanced load

Each system is composed of several phases, is either symmetric or asymmetric.Symmetry is determined by the symmetry of the electromotive force, voltage, and current.Main symmetry property is that the sum of instantaneous values ​​of numbers that form this system at all times be zero.Thus, equality phase gradient amount zero.

There are two basic ways for a bunch of bases in a system of several phases Association star or polygon.At the beginning of the star connection of all phases of the components are combined in a common node, which is considered to be a neutral point, respectively, to the connection ends.When connecting a polygon, all the parts are combined into a closed circular path, and all the neighboring elements are connected beginning and the end.When analyzing systems with many phases introduced many concepts that are needed to characterize the situation.The wires that connect Reproducers and load defined as linear, and vascular bundles that connect the point of neutrality predecessors and took the load of the neutral wires.

symmetrical system of three phases is often depicted graphs, vectors, trigonometric functions and complex variables rather complicated in construction.

receivers that are connected to the three-phase circuit, the phases may vary.You can take single-phase or three-phase.As an example, single-phase, it is possible to use incandescent lamps, lighting (fluorescent lamps, lamp, LED lighting, kettles with lighting), home appliances (iron, refrigerator, television, microwave, washing machine), motors (motors).As the three-phase - induction motors, induction furnaces.